Table 3.

ANA prevalence in the U.S. female population ages 20 years and older in NHANES (1999–2004) by exogenous hormone use

	Premenopausal				Postmenopausal
			Weighted	POR			Weighted	POR
	N^a	N ANA+^a	% ANA+ (95% CI)	(95% CI)^b	N^a	ANA+^a	% ANA+ (95% CI)	(95% CI)^b
Oral contraceptives
Never	209	46	19.9 (14.2–27.1)	(Reference)	391	71	19.7 (15.0–25.6)	(Reference)
Current	94	16	17.4 (11.3–25.6)	0.70 (0.36–1.36)	0	0	—	—
Past	478	87	19.2 (15.6–23.4)	0.64 (0.44–0.93)	327	55	15.6 (12.0–20.2)	1.22 (0.77–1.94)
P^c			0.876				0.224
Oral contraceptives, total years of use
Never used	209	46	19.9 (14.2–27.1)	(Reference)	391	71	19.7 (15.0–25.6)	(Reference)
<1 year	121	16	16.6 (9.5–27.5)	0.47 (0.24–0.93)	64	9	11.8 (6.3–21.1)	0.96 (0.41–2.26)
1–2 years	115	31	28.8 (19.5–40.4)	1.15 (0.63–2.09)	78	9	9.3 (4.2–19.4)	0.69 (0.27–1.76)
3–5 years	136	22	17.7 (10.8–27.4)	0.60 (0.33–1.12)	63	10	15.1 (9.8–22.5)	1.31 (0.63–2.75)
6–10 years	124	21	14.0 (8.4–22.4)	0.54 (0.31–0.96)	74	15	23.2 (11.9–40.3)	1.47 (0.78–2.78)
>10 years	73	13	18.1 (10.3–29.8)	0.59 (0.27–1.30)	43	9	15.4 (7.9–27.9)	1.45 (0.60–3.50)
P^c			0.338	0.232			0.321	0.134
Any use of estrogen pills or patch
Never	722	142	19.9 (16.8–23.4)	(Reference)	387	69	19.4 (14.7–25.3)	(Reference)
Current	30	4	9.1 (2.8–25.8)	NS	164	29	16.3 (10.4–24.5)	1.34 (0.75–2.37)
Past	17	1	8.4 (1.1–43.0)	NS	147	21	14.3 (9.8–20.5)	0.89 (0.56–1.43)
P^c			0.073				0.339
Estrogen pills/patch, years used
Never used	722	142	19.9 (16.8–23.4)	(Reference)	387	69	19.4 (14.7–25.3)	(Reference)
<1 year	20	1	2.4 (0.3–16.1)	NS	47	8	19.4 (6.7–44.5)	1.13 (0.44–2.93)
1–4 years	12	1	11.4 (1.5–51.9)	NS	66	9	12.0 (6.5–21.2)	0.90 (0.41–1.95)
5–9 years	10	1	10.3 (1.4–48.3)	NS	60	8	12.1 (5.9–23.2)	1.03 (0.47–2.25)
10+ years	5	2	29.3 (5.1–76.3)	NS	135	25	17.5 (11.2–26.3)	1.24 (0.72–2.16)
P^c			<0.001				0.476	0.697

Abbreviation: +, positive.

↵^aN is the number of subjects within the sample, not an estimated count for the U.S. population; % is adjusted for sample weights; individual totals for each variable may vary due to the number of missing or “don't know” responses.
↵^bPOR and 95% CIs estimated by survey logistic regression, adjusting for age, race/ethnicity, and PIR. Values were not calculated (—) where numerically infeasible or not shown (NS) for categories with fewer than 5 ANA-positive women.
↵^cP value for the Wald χ² test for general association or linear trend test in regression models for POR.